SYRACUSE, N.Y. -- State regulators this afternoon approved a $113 million increase in Upstate electric rates for National Grid that will implemented in a way that does not increase customer bills.

Today’s decision by the state Public Service Commission also creates the likelihood that large commercial and industrial customers will get significant rate cuts next year.

To keep customer bills from rising this year, the PSC postponed National Grid’s ability to collect at least $113 million in pension cost increases and other expenses until 2012 or later.

Next year is an important watershed, because the utility’s “competitive transition charge,” which adds some $570 million this year to customer bills, will expire at the end of 2011. That should enable the utility to lower bills for at least some customers while also recovering its deferred expenses. Because commercial and industrial customers pay the highest proportion of CTC charges, their bills are likely to be affected most when the charge expires.

National Grid officials could not be reached immediately for comment, but they are likely to be unhappy with today’s decision, which gives them less than one-third of the rate hike they had asked for. In a letter to the PSC Wednesday, company officials said the anticipated rate increase was not sufficient to cover increased costs.